Some players will adore the power of the metagame. Many things which can't be utilised by your character aren't traded to other women and men. Each power helps out in various situations throughout your trip, and the simple fact that you could swap powers at any time usually means that you are able to develop into an unstoppable force because of the Old Gods.
The biggest of which is that in case you do not specifically understand what it is you're doing, you are able to very quickly end up getting a character that's too weak to do much of anything. It's possible to also assign skills and runes very easily, which means that you won't need to change out your skills by developing a new character altogether. You are going to want to create several characters with a variety of builds instead of specialized classes.
The One Thing to Do for Path of Exile Orbs

API interfaces that are currently available are listed here. Experience scaling in PoE is a bit complex. A good example of two-sided stencil implementation is found in the ShadowVolume10 Sample.
The Basics of Path of Exile